The Festo CECX-X-C1 Modular Master Controller with CoDeSys and CECX-X-M1 Modular Controller with CoDeSys and SoftMotion do not require authentication for connections to certain TCP ports, which allows remote attackers to (1) modify the configuration via a request to the debug service on port 4000 or (2) delete log entries via a request to the log service on port 4001.